184. Check if Pangram

A pangram is a sentence where every letter of the English alphabet appears at least once.

Given a string sentence, return 'true' if it is a pangram, 'false' otherwise.

The check is case-insensitive.

Input: A single string sentence.

Output: Return 'true' if all 26 letters appear, otherwise 'false'.

Examples

Example 1

Input: thequickbrownfoxjumpsoverthelazydog
Output: true
Explanation: Contains all 26 English letters.

Example 2

Input: leetcode
Output: false
Explanation: Many letters are missing.

Example 3

Input: abcdefghijklmnopqrstuvwxyz
Output: true
Explanation: Exactly all 26 letters present.